Variable speed feed mechanism for railway sewing machine



Nov. 22, 1955 N. L. GENTRY ET AL VARIABLE SPEED FEED MECHANISM FORRAILWAY SEWING MACHINE 3 Sheets-Sheet 1 Filed Sept. 4, 1953 m mg E a Wm16M Z Z Z w WL N@ M w 0 m fi w w w L IHIHHI ATTORNEYS Nov. 22, 1955 N.L. GENTRY ET AL 2,724,352

VARIABLE SPEED FEED MECHANISM FOR RAILWAY SEWING MACHINE Filed Sept. 4,1953 3 Sheets-Sheet 2 INV ENTL )RS Norman L. Gert fry, Lewis Pope Q1LemueL/l. M 0011 iel BY 4 M w Nov. 22, 1955 N. 1.. GENTRY ET AL2,724,352

VARIABLE SPEED FEED MECHANISM FOR RAILWAY SEWING MACHINE Filed Sept. 4.1955 3 Sheets-Sheet 3 IN VENTORS Lewis I IPo ve 4 Lemuel/1.11 "Daniel BYW ATT( )RNEYS 2,724,352 Patented Nov. 22, 1955 VARIABLE SPEED FEEDMECHANISM FOR RAILWAY SEWING MACHINE Norman L. Gentry, Lewis V. Pope,and Lemuel A. McDaniel, Phenix City, Ala.

Application September 4, 1953, Serial No. 37 8,622

Claims. (Cl. 112-2) Our invention relates to the sewing together ofrelatively short lengths of cloth that come from a loom to form acontinuous length of approximately 1000 yards so that the material maybe subjected to finishing operations .such as dyeing, bleaching,sanforizing and mercerizing machine head along Weft-wise of the cloth.This latter arrangement is usually called a :railway sewing machine.

Our invention is directed to means for feeding a railway sewing machineat such speeds that at selected positions, a larger number of stitchesmay be produced per unit of length as contrasted with other positionsalong the seam.

Another object of our invention is to provide anattachment for a railwaysewing machine whichwill without altering the machines structure easilyprovide for moving the sewing machine along its rails at alternate slowand higher speeds thereby alternately producing a greater and a lessernumber of stitches per unit of length of the seam being made.

A still further object of the invention is to provide an alternatelyvariable speed drive for moving the railway sewing machine along itstrackat different speeds which includes a simple clutch and gearingmechanism that may be easily attached and driven by the usualmotor drivefor the railway sewing machine.

Another object of our invention is to provide an attachment for arailway type of sewing machine which includes a variable speed driveinterposed between the motor and the traversing mechanism carrying thesewing machine and adjustable positioned operators along the machinewhich cause the variable speed drive mechanism to shift alternately froma high speed to a slow speed or vice versa.

Still further objects and the entire scope of applicability of thepresent invention will become apparent from the detailed descriptiongiven hereinafter; it should be understood, however, that the detaileddescription and specific example is given by way of illustration onlyand, while indicating the preferred embodiment of the invention, is

not given by way of limitation, since various changes and modificationswithin the spirit and scope of the invention will become apparent tothose skilled in the art from this detailed description.

For a more complete understanding of our invention reference is had tothe following description and drawingsin which;

Fig. l is a fragmentary plan view of a typical railway type sewingmachine having our variable speed drive attached;

Fig. 2 is an end view of the machine of Fig. 1 as seen from theright-hand end; i

Fig. 3 is a fragmentary rear view of the machine showing our variablespeed drive attached;

Fig. 4 is an enlarged cross sectional view of the variable speed driveattachment taken along line 44 in Fig. 3;

Fig. 5 is a cross sectional view of the variable speed drive mechanismas viewed along line 5-5 in Fig. 4;

Fig. 6 is a cross sectional view along line 6-6 of Fig. 4;

Fig. 7 is a fragmentary cross sectional view of the clutch collar andactuating arm therefor taken along line 77 of Fig. 4;

Fig. 8 is a cross sectional view of one of the clutches as viewed alongline 88 in Fig. 4; and

Fig. 9 is a cross sectional view of another of the clutches in thevariable speed drive mechanism as viewed along line 99 of Fig. 4.

Throughout the various figures in the drawing and the description likereference characters refer to similar parts.

Referring to Figures 13, a railway type sewing machine is generallyindicated at 10. The customary rails 11 and 12 supported on a base 13support a slidable bed plate or carriage 14 which is held on bydove-tailed joints 15. Attached on the inside vertical surface of one ofthe rail members such as 11 is a toothed rack 16. A vertical shaft 17which extends above and below bed plate 14 is supported therein by abearing 18 and has attached at its bottom end a gear 19 which mesheswith the rack 16 while its upper end has another gear 20 attached bysuitable clutch mechanism controlled by the knurled hand wheel 21. Bymeans of the clutch connection controlled by wheel 21, gear 20 may becast loose from the vertical shaft 17 as when it is desired to move thebed plate 10 along its supporting rails by hand. p

. Still referring to Figures l3 a pair of pillow blocks 22 mounted oncarriage 14 support a transverse drive shaft 23 having a worm gear24secured thereto which meshes with and drives gear 20. A sewing machinegenerally indicated at 24 has a needle sewing head 25 and'a needle 25'therein. At the rear of the sewing machine 24 is its drive shaft 26having a sprocket 27 fixed. thereto. A support rack 28 is provided atthe front of the machine and it extends through its length adjacenttheneedle 25'. The rack 23 supports the two ends of cloth to be seamedtogether such as indicated at C and C in Fig. 2. Suitable cloth.engaging clamps 29 having clamping screws 29 thereon are slidablymounted on the cloth rack 28.

A pair of vertical standards 30 attached at their bottom ends tocarriage 14 support a motor mounting shelf 31 at theirupper ends.Mounted on shelf .31 is a motor 32 having a. drive sprocket 33 overwhich is led a drive chain 34 about the drive sprocket 27 on the sewingmachine 24 and over the drive sprocket 35 of the variable speed drivemechanism 36 to be described hereinafter.

In Figures l-3 the variable speed drive mechanism is generally indicatedat 36 and in Figures 49 it is shown in detail.

Reference to Figures 4-7 shows a box-like housing 37 for the variablespeed drive which is supported on an outwardly extending shelf-likebracket 33 attached to the rear of the carriage 14 as illustrated bestin Figure 2. Disposed just below mounting shelf 38 is an elongated bar39 which extends for substantially the length of the railway sewingmachine 10 and is supported therefrom by brackets 40-40, best shown inFig. l. Mounted on bar 39 is a pair of adjustable positional dogs 41having knurl headed set screws 42 for securing them in selected positionalong rod 39. Each of the dogs 41 has carnsurfaces 41 and 41" againstwhich rides an operating lever 43 on the variable speed drive mechanism36 when the 3 carriages 14 ..carrying...all the mechanism .has .beenmoved into position.

.Varialzle speed drive mechanism The variable speed drive mechanismgenerally indicated -at-.-3.6saccording :tto,.our. inventionand housedwithin box enclosure 37 will now be. described.

The:adjustablypositionable dogs 41 on the attached bar ;.-39,.above-described,-:-shift the-variable speed drive from a high to a lowspeed for moving the carriage 14 and the ;sewing;machine 243thereoneitherata' high or a low'speed. This traverse of .theasewing machine:when its needle runs at a constant: speedcauses a largenumber ofstitches per .inch-to.be .made in the selvage edges of. the pieces ofcloth b'eing joinedwhen thei;traverse is atwa low speed. Conversely,when the traverse speed is high, thenumber of stitches, per inch oftravel -over.the cloth is low.

The variable speed drive mechanism has an input shaft mountedin bearings45 in the opposite walls 37a and 3750f box '37; ta counter.shaft-46-belowand parallel to shaft 44 mounted in similar end bearings45 as .for shaft 44 also .positioned in opposite walls 37a and 37b; ofbox .37; anclanwoutput shaft 48 also parallel tojshafts=44-and 46;.butto one. side and intermediate thereof and-mounted in bearings 49 inwallst37a and 37b.

Input shaft :44 has rotatably mounted thereona thirty- 7 six tooth spungear.50 adjacentywall 37a. Gear -50,has formed therein a radial recesswhichis threaded to; receive a screw plug 52 which holds in place aspring 53 which urges a ball.54 into an. annular recess v55 formedaboutltheadjacent position of shaft 44 whereby axial displacement of gear'50along shaft 44 is prevented yet the gear '50 is permitted to freelyrotate on shaft 44. Gear50 is formed with an internal axially disposedcone surface 56 for engagement by aclutch element 57 slidably mounted onshaft-.44. I

'Referring to Fig. 8, slidable clutch element 57 has .a cone face 57 ofcorresponding shape to cone surface 56 in gear 50 and a suitableanti-friction covering 58 is aflixed to surface"57'. Clutch element 57is formed with a keyway'59, in which is slipped a key'60 which fits in akeyway in shaft '44 and thus keys it to shaft 44 for rotation therewithbut permits the element 57 tov slide axially along shaft 44. Clutchelement 57 is formed with an annular "recess'61 therein which receives aU-shaped operating collar 62; seeFigures 7 and 8.

The operating-mechanism for clutch '57 consists of the mechanism*generallyindicated at '63, see Figures 4, -and-'7,"andispivotallymounted inwall 37c by a collar 64-which=extends throughthe wall and provides a bearing 5 for-'shaft 65. *Shaft- 65 is formed onits inner 'end with a I crank arm 66-extendingin the same direction fromshaft 65 :as operating-lever 43 and having a reduced inner endpinportion 67'68'which is received in apertures'62 and '62"respectivelydnthe- U-shaped collar 62. The outer end of shaftl65 has theoperating handleor lever 43' securedtheretoras by the split take-upcollar 43' attached to the .endihereofand secured in adjusted positionby take-up screw:43",.=see: Fig. 4. When handle 43 strikes the cam:surfaces 41' and 41" of dog 41, see Fig. 1, crank arm 66 is-pivotedthus'moving collar 62 out away from gear 50 and in turn clutch element57 is disengaged from gear 50;;permitting. gear 50 to rotate on shaft44.

.In Fig. 4 there 'isshown fixed to the other end of shaft 44,. oppositeto gear 50, an eighteen tooth spur gear 70 keyed to shaft 44 by a key71, see Fig. 6. Disposed about shaft44 and between .clutch element 57and the integral .hub 70 of'spur gear 70 is a spiral spring 72 whichconstantly urges clutch element 57 into engagement with the clutchsurface 56 in gear 50 thus causing shaft 44 .and .clutch element-57vto.drive gear 50. However, when the operating handle 43 strikes camsurfaces 41 and 41" on dog41, the clutch elementis slid along shaft 44and its key toward gear'70, compressing spring '72 and disengagingclutch.el ement"57 and itsfacing 58 from theconical surface 56" in, gear'50.

Continuingthedrivefrom gear 70in this variable speed drive mechanism,gear 70.n1eshes with a fifty-four tooth gear which has a clutch hub 81by which it is mounted on the end of the countershaft 46 adjacent wall37b. Hub 80 has an outer circular perimeter 81' over which is rotatablymounted the circular. inner portion 80 of gear 80. Hub 81 is formed witha central collar portion 82 which is keyed to shaft 46 bykey 83.-Reference to Fig. 4 shows the outer end of spring 72. on shaft 44pressing against the inner face of hub 70 of gear 70. Hub 81, see Fig.v9, hasmilled therein four inset tangentially-like pockets 84 having acylindrical recess 85 drilled in the base of each pocket to receive aspring 86 which presses against a roller-87. Thus, gear 80 may rotatecounterclockwise, see Fig. 9, about hub 81 since the rollers 87 willmove in pockets 84 against springs 86 and relative movement between gear80 and its hub 81 is permitted. However, undercertainconclitions as willbe described hereinafter, gear 80 rotates .with hubt81. Thus, there isprovided an over riding clutch between gear? and the hub181 which mountsit on shaft 46. The gear80 isheld onhub 81 by end plates 88, seeFigures4 and 6, which plates are held in place1by screws 89 threadedly receivedin the gear 80. The endplates 88 permit gear '80 to rotate relative toits mounting hub:81.

As shown in Figures 4 and 5 countershaft46 has fixed thereto athirty-six tooth spur gear '90 as by a key 91. Gear 90 meshes with gear50 and is driven thereby when clutch'element 57 is .in drivingengagement otherwise when the clutch element is out of engagement, gear90 drives gear 50-which is then free .to rotate on shaft 44.

Output shaft 48, best shown in Figures 4 and 5, has a thirty-sixtoothspur gear;1001keyed thereon as by'key ltllso that it meshes withandis driven by spur gear 90. The end of output shaft 48 is coupled todrive shaft 23 of the traversing mechanism of the sewing machine by acoupling. 102 as shownv in Figures 1, 2 and 4. Coupling 102 replaces thenormal'drive sprocket which heretofore Operation A primary object is tojoin together two'pieces of cloth C and'CQas shown in Fig. 2, preferablyin abutt end fashion by stitching of the Merrow type and in so doing toprovidefor a short'distance at each end ofthe-selvage edge,ia greaternumber 'of'stitches per inch than-over the restofthe span of thebuttedseam which joinsthe selvage edges. This provides for rapid seamingyet affords a .durableseam whichholds thepieces ofcloth together-so thatfinishing operationsmay be performed with ithe assurance'that'the seam.will nottear apart.

Our variable speed jdrive attachment 36rwithithe-1attached 'rod i39wand.the adjustable .positionableudogs :41 thereon when attached to arailwaysewinglmachine such as described'affordsa joining seam for cloth elfdsasljust above described.

The dogs 41are set in the position'desired toward each end .ofrod39in'keeping-with the vposition ofthe ends of the selvage edges ofthe cloth clamped in-clamp 28:.to-be joined together bya seam sewn bythe .sewingt-machine 24'. The hand wheel 21 on the traversing mechanismis released so thatgear L24is free from vertical-ishaftz fl and thebedjplate 14 carrying its mounted ,membernmay bemoved to the startingedge of the cloth pieces'C'and C to be joined together .by-a buttedseam. lThen .ihand wheel.21'is again tightened. Depending control arm43of the variable speed drive mechanism is Iridingaupaon the. straightcam; surface/ 41" of dog-41 andthus crank arm 66,.seezEiguresS-andfi, isrotatedinthe samerdirection as arm 43, namely, back beyond the;.planexof,the

paper asdepicted in Eigures 5 and. 7. When this,,o,ccurs collar 62.011.clutch element- 57,. slides the element to,,the right along shaft '44,see Fig. 8, and the c1utch,-'facigg" 56 is out of engagement with theconical clutchsti'rfa'c'ein gear 50. Gear 50 is then in a condition notto be driven by shaft 44. i l

The motor 32is then energized and the seam is made by the sewing machine24' as the carriage 14 is first slowly moved over rails 11 and 12 fromthe right hand end of the machine, see Fig. 1, towards the left-handend. A

. .The traverse drive for the carriage 14 is through the variable speedgearing enumerated hereinafter. Chain 34 drives sprocket 35 and inputshaft 44 at a constant speed. Spur gear 70 011 the outer end of shaft 44when rotated counterclockwise drives gear 80 clockwise with on shaft 23drives gear and it in turn rotates shaft 17.

Gear 19 fixed to shaft 17 and in mesh with the tooth rack 16 causes thecarriage 14 carrying its attached medium to move along the supportingrails 11 and 12. The sewing machine 24' thus moves slowly from right toleft and the stitches are placed closely together in cloth. pieces C andC until handle 43 moves out of engagement with the cam surfaces 41 and41, see Fig. l, whereupon the clutch element 57 moves to the left, seeFig. 8, along shaft 44 under the influence of compression spring 72 andgear 50 is then rotated by shaft 44.

While shaft 44 is rotating counterclockwise, see Fig. 5, it is drivinggear 50 and shaft 46 clockwise. Hub 81 on shaft 46 and a clutch withingear 80 is rotated clockwise but at a higher speed than at which gear 80is rotated by gear 70 on shaft 44. Gear 80 is thus coupled tocountershaft 46 by an over-riding clutch. In other words the clutchelements in hub 81. permit the gear 80 to, rotate at a different speedthan the speed of the hub 81. Gear 90 rotating at relatively high speedby being now driven .by gear 50, rotates gear 100 at the same high speedsince each of the gears 50, 90 and 100 have the same number of teeth,for example thirty-six teeth. Shaft 48 on which gear 100 is fixedthrough itscoupling 102 in turn drives shaft 23 at high speed.

, seam which is strong yet the speed of sewing in the seam large numberof stitches per inch oftravel are sewn by the machine, such astwenty-four stitches per inch.

Shaft 23, as before, drives gear 24, shaft 17 and gear 19 at arelativelyhigh speed and the gear. 19 meshing with the toothed rack 16affixed to the machine causes the carriage 14 to move at relatively highspeed. The sewing machine 24 carried by bed plate 14 then moves atrelatively high speed as contrasted with the prior slow speed, and afewer number of stitches per inch are sewn into the cloth pieces C andC. For example, eight stitches per inch are made in the seam. Thiscontinues until the carriage 14 has traversedto the left hand end of therails 11 and 12 when clutch control lever 43 strikes the end dog 41 andthe cam surfaces 41' and 41" causing the clutch element 57 to becomedisengaged again from gear 50 and the slow speed drive takes over asbefore. With this slow speed drive a large number of stitches per inch,

for example twenty-four per inch, are made in the seam at the other endof the selvage edge of the pieces of cloth C and C.

Our variable speed drive attachment is easily manufactured and may beinstalled on railway sewing machines such as of the type describedwithout altering the maversion mechanism which permits the making of abutted has not been decreased to any marked extent.

We claim as our invention:

1. In a traveling sewing machine outfit; a railway; a carriage on saidrailway; a sewing machine mounted on said carriage; driving mechanism topropel said carriage along said railway and having a drive shaft;variable speed driving mechanism mounted on said carriage for drivingsaid shaft at a variable speed to move said carriage at a variable speedalong said railway; means mounted on said carriage to drive said sewingmachine and said variable speed driving mechanism; and a control deviceadjustable on and lengthwise of said railway to vary the speed of saidvariable speed driving mechanism; said variable speed driving mechanismcomprising a housing having mounted therein a constant speed inputshaft, said input shaft having rotatably mounted thereon a first gear, afirst clutch detachably connecting said first gear to said input shaft,and a second gear fixed to the input shaft, a countershaft in spacedrelation and parallel to said input shaft, said countershaft having afirst gear 3 coupled thereto by an over riding clutch, said last namedgear being in mesh with said second gear on the input shaft, saidcountershaft having a second gear fixed thereto and in mesh with saidfirst gear on the input shaft, an output shaft in parallel spacedrelation to said input and countershafts and having a gear fixed theretoin mesh with said second gear on the countershaft, operating means forsaid first clutch on the input shaft and having an operating armextending from said housing for operative engagement with said controldevice adjustable on and lengthwise of said railway; and means couplingsaid output shaft to said drive shaft of said driving mechanism topropel said carriage along said railway.

2. A traveling sewing machine outfit according to claim 1 wherein saidover riding clutch gear attached to said countershaft comprises a hubadapted to be keyed to the countershaft, said hub having a plurality ofequally spaced tangentially disposed recesses formed in an outercircular portion thereon, spring pockets formed adjacent and in linewith said recesses, coil springs seated in said pockets and a roller ineach of said recesses pressed by said coil spring therein, an annulargear mounted over said circular portion of the hub having the insideannular surface thereof in contact with said spring pressed rollerswhereby on rotation of said annular gear in the same direction as saidsprings press said rollers, said hub is frictionally coupled throughsaid rollers to said annular gear and rotated in the same directiontherewith and when said hub is rotated by the countershaft to which itis attached and at a greater speed than said annular gear, said annulargear slips with respect to said hub.

3. In a traveling sewing machine outfit having a railway, a carriage onsaid railway, a sewing machine mounted on said carriage along saidrailway, said driving mechanism having a drive shaft, the improvementcomprising a variable speed driving mechanism for driving said driveshaft at a variable speed to move said carriage at a variable speedalong said railway, said variable speed mechanism comprising a controldevice adjustable on and lengthwise of said railway to control saidvariable speed mechanism, a housing adapted to be supported by saidcarriage, said housing having a constant speed input shaft, said inputshaft having rotatably mounted thereon a first gear, a first clutchdetachably connecting said first gear to said input shaft, and a secondgear fixed to the input shaft, a countershaft in spaced relation andparallel to said input shaft, said countershaft having a first gearcoupled thereto by an over riding clutch, said last named gear being inmesh with said second gear on the input shaft, and a second gear fixedto the countershaft in mesh with said first gear on the input. shaft, anoutput shaft in parallel spaced relation to said input and countershaftsand having a gear fixed thereto in mesh with said second 1 gear on thecountershaft, operating means for ing arm extendingfrorn s aid housingffor operaitiveengage rnent with saidcontrolfdeyice adjustable on andlens; wise of said railway, and means coupling said out- 1 put shaft to,sa'id 'd'rivefshaft ofi said Idriying mechanism to propelsaidcarriagealong said railway.

4. A traveling sewing machine outfit of the character described inclaim! 3 whereinsaid first clutch has an element'thereofslidably-mounted on saidrinput shaft, said input shaftofjthe variablespeed-driving mechanism has mounted "thereon a spring which is disposedbetween said fclutch element 's'lid'able onthe input shaft and saidsecond geaffixed to. the input shaft for urging said clutch intoengagement withsaidfirst gear whereby said input shaft drives the firstgearthroughsaid clutch.

"5. Altraveling sewing vmachine outfit of the character ljdescfibedlinclaim 3 wherein .said over riding clutch gear lattaf'ched jtosaidtcounterlshaft comprises a hub adapted ,to be keyed to the "inputshaft, said hub having a plujrality of equally spaced tangentially-likedisposed recesses formedin an outer circular portion thereof, springpockets' formed adjacent and in line with said recesses, coil springsseated in said pockets and a roller in'each ofts'a'id recesses pressedby vsaid coil spring thereinvan' annular r gear mountedover saidcircular portion-ofthefhubf hav ing the inside annular: surface ithereof' in contact with said spring pressed rollers whereby on rotationof said annular gear in the same direction as said springs press saidrollers, said hub is frictionally coupled through said rollers to saidannular gear and rotated in the same direction therewith and when saidhub is rotated -by the eountershaft to which it is attached and at agreater speed than said annular gear, said annular gear slips withrespect to said hub.

References Cited in the'file of this patent UNITED STATES PATENTSRemington Dec.- 21, 1943

